Heterocyclic red azo colorants for seed treatment applications

Abstract

This invention relates to heterocyclic red azo colorants for seed treatment applications. The red azo colorants contain a heterocycle that includes one nitrogen atom and one sulfur atom and are free from electron-withdrawing groups on the heterocycle. Seeds for use in horticultural/agriculture applications that are coated with the heterocyclic azo colorants provide anti-counterfeiting properties to the coated seeds. A color change phenomenon is observed when the coated seeds are exposed to an acidic material, such as vinegar, and provides evidence of the authenticity of the coated seeds. The invention also relates to agricultural formulations containing the heterocyclic red azo colorants that can be used as an anti-counterfeit agents.

We claim: 
     
       1. A composition comprising:
 (a) an agricultural formulation that includes at least one agricultural active ingredient, and 
 (b) at least one red azo colorant represented by the following formula: 
 
       
         
           
           
               
               
           
         
         wherein R 1  is a heterocyclic group comprising at least one 5 membered ring incorporating one N and one S atom within the ring system, and wherein the heterocyclic group is free from electron-withdrawing groups; 
         R 2  and R 3  are independently selected from the group consisting of H, alkyl, and poly(oxyalkylene) moieties, wherein at least one of R 2  and R 3  is a poly(oxyalkylene) moiety; and 
         R 4  is independently selected from the group consisting of H, alkyl, substituted alkyl, substituted nitrogen, hydroxyl, halogens and ethers. 
       
     
     
       2. The composition of  claim 1 , wherein the agricultural formulation is present in the composition in an amount in the range from 95% to 99.999%. 
     
     
       3. The composition of  claim 1 , wherein the at least one agricultural active ingredient is selected from the group consisting of fungicidal agents, insecticidal agents, nematicidal agents, biological agents, pesticides, biocides, rodent killers, weed killers, plant growth regulators, plant growth stimulators, nutrients, hormones, and any combination thereof. 
     
     
       4. The composition of  claim 1 , wherein the at least one red azo colorant is present in the composition in an amount in the range from 0.001% to 95%. 
     
     
       5. The composition of  claim 1 , wherein R 1  is selected from the group consisting of thiazole, isothiazole, benzisothiazole, and benzothiazole. 
     
     
       6. The composition of  claim 5 , wherein R 1  is selected from thiazole and benzothiazole. 
     
     
       7. The composition of  claim 1 , wherein R 1  includes one or more substituents on the 5-membered ring incorporating one N and one 5 atom selected from the group consisting of H, alkyl, substituted alkyl, hydroxyl, substituted hydroxyl, aryl, and substituted aryl. 
     
     
       8. The composition of  claim 1 , wherein poly(oxyalkylene) moieties are selected from ethylene oxide, propylene oxide, and butylene oxide, or combinations thereof. 
     
     
       9. The composition of  claim 1 , wherein the total number of alkylene oxide residues per colorant molecule is in the range from 4 to 250. 
     
     
       10. The composition of  claim 1 , wherein the total number of alkylene oxide residues per colorant molecule is in the range from 5 to 100. 
     
     
       11. The composition of  claim 1 , wherein the total number of alkylene oxide residues per colorant molecule is in the range from 5 to 20. 
     
     
       12. The composition of  claim 1 , wherein the composition exhibits a change in color from red to violet in the presence of an acidic material with a pH ≤3. 
     
     
       13. A coated seed containing the composition of  claim 1 . 
     
     
       14. A seed coated with the composition of  claim 1 , wherein the composition further includes at least one of a polymeric binder and a film-forming polymer. 
     
     
       15. A composition comprising:
 (a) an agricultural formulation that contains at least one agricultural active ingredient, and 
 (b) at least one red azo colorant selected from Formulas I and II: 
 
       
         
           
           
               
               
           
         
         wherein R 2  and R 3  are independently selected from the group consisting of H, alkyl, and poly(oxyalkylene) moieties, wherein at least one of R 2  and R 3  is a poly(oxyalkylene) moiety; 
         R 4  is independently selected from the group consisting of H, alkyl, substituted alkyl, substituted nitrogen, hydroxyl, halogens and ethers; and 
         R 5  is independently selected from the group consisting of H, alkyl, substituted alkyl, hydroxyl, substituted hydroxyl, aryl, and substituted aryl. 
       
     
     
       16. The composition of  claim 15 , wherein the total number of alkylene oxide residues per colorant molecule is in the range from 5 to 20. 
     
     
       17. A seed coated with the composition of  claim 15 . 
     
     
       18. A composition comprising:
 (a) an agricultural formulation comprising at least one agricultural active ingredient, and 
 (b) at least one red azo colorant represented by Formula III: 
 
       
         
           
           
               
               
           
         
         wherein R 2  and R 3  are independently selected from the group consisting of H, alkyl, and poly(oxyalkylene) moieties, and wherein at least one of R 2  and R 3  is a poly(oxyalkylene) moiety. 
       
     
     
       19. A seed coated with the composition of  claim 18 . 
     
     
       20. A composition comprising:
 (a) an agricultural formulation comprising at least one agricultural active ingredient, and 
 (b) a red azo colorant represented by Formula IV: 
 
       
         
           
           
               
               
           
         
       
     
     
       21. A seed coated with the composition of  claim 20 .